JPS645051B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a highly rigid and highly melt viscoelastic polypropylene for post-processed sheets and blow molding, and a method for producing the same. More specifically, the present invention achieves the above-mentioned high rigidity and high melt viscoelasticity by polymerizing propylene in multiple stages using a specific catalyst so that it is composed of a polymer portion having two constant melt flow indexes. This article relates to polypropylene used in combination with the polypropylene and its manufacturing method. The present invention also relates to a polypropylene with excellent post-processability (sometimes referred to as sheet formation) and blow moldability, and a method for producing the same. Sheets manufactured by processing known polypropylene tend to sag quickly during heat forming for post-processing (or secondary processing), have a narrow range of processing conditions, have poor forming efficiency, and are wide sheets. However, there are disadvantages such as the above-mentioned drooping is large, the thickness of the post-processed product tends to be uneven, and weight wrinkles tend to occur. For this reason, only small molded products can be manufactured. On the other hand, when using known polypropylene for blow molding, there are the following problems. That is, since the parison sags significantly during molding, the thickness of the molded product becomes uneven. For this reason, the blow molding method can only be applied to small products.
If high molecular weight polypropylene is used to prevent the above-mentioned sagging, there will be poor fluidity, a large load during molding, large energy loss, the risk of mechanical troubles, and the molded product will become rough and lose its commercial value. It is. Several proposals have been made to improve the above-mentioned sheet formability and blow moldability of polypropylene. For example, Japanese Patent Publication No. 47-80614 and Japanese Patent Publication No. 50-8848,
This is a method of mixing polypropylene with low density polyethylene, etc. However, molded products using such mixtures tend to have rough surfaces, and to prevent this, strong kneading is required during melting, which limits the selection of kneaders and power consumption. Further, JP-A-56-70014 discloses a two-step copolymerization method, and proposes a method of imparting a difference in molecular weight and a difference in the amount of polymer between the polymer parts produced in each step. However, the melt flow properties of the copolymers obtained by this method are insufficient. Furthermore, Japanese Patent Application Laid-Open No. 118906/1983 discloses a method for maintaining a constant relationship between the melt expansion ratio (hereinafter referred to as SR) of polypropylene and the melt flow rate. However, this method does not consider the relationship between the melt flow rate and the flow characteristics during melting, and SR cannot be uniquely determined by the relationship with the extrusion shear rate of molten polypropylene. It is not necessarily possible to improve the processing characteristics of Furthermore, known polypropylene has low rigidity and softness compared to polystyrene or ABS resin, etc., so it cannot be used as a material for molded products that require higher rigidity and higher hardness, and this is a serious bottleneck in expanding the use of polypropylene. It is becoming. If the rigidity of polypropylene can be improved, it will be possible to make the molded product thinner depending on the degree of improvement, which will not only be effective in saving resources, but will also speed up the cooling rate during molding, increasing the molding speed per unit time. This makes it possible to contribute to improving productivity in molding. Known techniques for improving the rigidity of crystalline polypropylene include, for example, a method of adding an organic nucleating agent such as paratertiary butylbenzoic acid aluminum salt or 1,3-2,4-dibenzylidene sorbitol to form the polypropylene. However, it is expensive and uneconomical, and its addition has the disadvantage that gloss impact strength, tensile elongation, etc. are greatly reduced. Other methods for improving rigidity include the use of various inorganic fillers such as talc, calcium carbonate, mica, barium sulfate, asbestos, and calcium silicate, but these do not impair the light weight and transparency that are the characteristics of polypropylene. Moreover, it has the disadvantage that impact strength, gloss, tensile elongation, additivity, etc. are reduced. JP-A-55-81125 is a technology that uses polypropylene with high isotacticity for the purpose of high-rigidity molded products, but the polypropylene used here is within the isotacticity range of the conventional technology. The effect of improving the rigidity of molded products is still insufficient. In view of the current state of the above-mentioned known technology, the present inventors have conducted extensive research in order to solve the problems of the above-mentioned known technology regarding improvements in the sheet formability, blowability and rigidity of polypropylene. As a result, propylene is polymerized in two stages in multiple stages using a specific catalyst system,
By regulating the relationship between the intrinsic viscosity of the polymer portion in each category within a certain range, and further regulating the quantity ratio of the polymer portion in each category, it is possible to achieve extremely high rigidity and The present invention was completed by discovering that polypropylene with significantly superior post-processability and blow moldability can be obtained. As is clear from the above description, an object of the present invention is to provide a polypropylene having good sheet post-processability, blow moldability, and high rigidity, which are not found in known polypropylenes, and a method for producing the same. Another purpose is to expand the specific fields of application of polypropylene sheet molded products and blow molded products, and to facilitate the production of high-quality molded products. The present invention consists of two inventions having the following configurations (1) to (12). (1) A solid product () obtained by reacting an organoaluminum compound () or a reaction product () of an organoaluminum compound () and an electron donor (A) with titanium tetrachloride (C) is further added with electrons. A solid product () obtained by reacting a donor (A) and an electron acceptor (B) is combined with an organoaluminum compound () and an aromatic carboxylic acid ester ().
Propylene is polymerized in multiple stages in the presence of a catalyst in which the molar ratio of the aromatic carboxylic acid ester and the solid product () is set to 0.1 to 10.0.
65% by weight in the second and subsequent stages.
to 35% by weight, and the first stage and the second stage
When the limiting viscosity of the middle molecular weight part of each polymer part produced after the stage is [η] _H , and the limiting viscosity of the lower one is [η] _L , 3.0 [η] _H − [η] _L 6.5... (1) A high-rigidity, high-melt viscoelastic polypropylene for post-processed sheets and blow molding, which is obtained by adjusting the intrinsic viscosity of each polymer part. (2) The polypropylene according to item (1) above, which has a melt flow index (M ₁ ) of 0.03 to 2.0 g/10 minutes. (3) The polypropylene according to item (1) above, wherein the organoaluminum compound () is a dialkylaluminum monohalide. (4) The polypropylene according to item (1), wherein the combination of the solid product () and the organoaluminum compound () is preactivated by reacting with α-olefin. (5) Isotactic pentad fraction (P)
The relationship with MFR is 1.0aP0.015log MFR+
The polypropylene according to item (1) above, which is within the range of 0.955. (6) Melt Flow Index (HMI) (10.8
Kg/10 minutes, 230℃) is the melt flow index (MI) (2.16Kg/10 minutes, 230℃) log HMI−0.922log MI1.44 ……(2) The polypropylene of item (1) above, which is obtained by adjusting the relationship. (7) Further electrons are added to the solid product () obtained by reacting the organoaluminum compound () or the reaction product () of the organoaluminum compound () and the electron donor (A) with titanium tetrachloride (C). The solid product () obtained by reacting a donor and an electron acceptor (B) is converted into an organoaluminum compound ().
and an aromatic carboxylic acid ester (), and propylene is polymerized in multiple stages in the presence of a catalyst in which the molar ratio of the aromatic carboxylic acid ester and the solid product () is set to 0.1 to 10.0. 35 to 65% by weight of the total polymerization amount in
65 or 35 in the second and subsequent stages
% by weight, and the limiting viscosity of the middle-high molecular weight part of each polymer part produced in the first stage and the second stage and subsequent stages is [η] _H The limiting viscosity of the lower one is [η] _L
3.0 [η] _H − [η] _L 6.5 ...(1) A method for producing high-rigidity and high-melt viscoelastic polypropylene, which is characterized by adjusting the intrinsic viscosity value of each polymer part. (8) The method for producing polypropylene according to item (7) above, wherein the melt flow index (M ₁ ) is 0.03 to 2.0 g/10 minutes. (9) The polypropylene according to item (7) above, wherein the organoaluminum compound () is a dialkylaluminum monohalide. (10) The method for producing polypropylene according to item (7) above, wherein the combination of the solid product () and the organoaluminum compound is preactivated by reacting with α-olefin. (11) Isotactic pentad fraction (P)
The relationship with MFR is 1.00P0.015log MFR+
The method for producing polypropylene according to item (7) above, wherein the polypropylene is within the range of 0.955. (12) Melt Flow Index (HMI) (10.80
Kg/10 minutes, 230℃) is the melt flow index (MI) (2.16Kg/10 minutes, 230℃) log HMI−0.922log MI1.44 ……(2) The method for producing polypropylene according to item (7) above, in which the relationship is adjusted. The polypropylene of the present invention is produced as follows. That is, propylene is polymerized in at least two stages using a so-called Ziegler-Natsuta catalyst consisting of a specific titanium trichloride composition, an organoaluminum compound, an aromatic carboxylic acid ester, and a molecular weight regulator. As a titanium trichloride composition,
The following is obtained from the solid product () obtained by reacting titanium tetrachloride with an organoaluminum compound () or the reaction product () of an organoaluminum compound () and an electron donor (A) with titanium tetrachloride (C). The solid product () obtained through the treatment is used.
(Note: A, C, etc. are symbols of the present invention to identify catalyst production raw materials or intermediates, and the same shall apply hereinafter.) Other titanium trichloride compositions may be used in place of this solid product (). Even if used, the purpose of the present invention cannot be achieved. The solid product () is produced as follows. First, (a) react the organoaluminum compound () and titanium tetrachloride (C), or (b) react the reaction product () of the former and the electron donor (A) with the latter to produce a solid product (). . In the case of (b), a more preferable titanium catalyst component can be obtained in the end. Method B is described in the specification of Japanese Patent Application No. 12875-1982 (Japanese Unexamined Patent Publication No. 110707-1982) and is as follows. Organoaluminum compound () and electron donor (A)
The reaction with is carried out in the solvent (D) at -20°C to 200°C, preferably -10°C to 100°C for 30 seconds to 5 hours. (),
There is no restriction on the order of addition of (A) and (D), and the ratio of the amount used is 0.1 to 0.1 to 1 mole of organic aluminum to electron donor.
8 mol, preferably 1-4 mol, solvent 0.5-5
Preferably, 0.5 to 2 is appropriate. Aliphatic hydrocarbons are preferred as solvents. The reaction product () is thus obtained. The reaction product () is in a liquid state after the reaction (reaction product liquid ()) without separation.
) can be used for the next reaction as is. The reaction between the reaction product () and titanium tetrachloride (C) is carried out at 0 to 200°C, preferably 10 to 90°C for 5 to 8 minutes.
Do time. Although it is preferred not to use a solvent, aliphatic or aromatic hydrocarbons can be used.
(), (C), and the solvent may be mixed in any order. It is preferable to complete the mixing of the entire amount within 5 hours, and after mixing the entire amount, further within 8 hours at 10°C to 90°C. It is preferable to continue the reaction. The amount of each used in the reaction is 0 to 3000 ml of the solvent per 1 mole of titanium tetrachloride, and the reaction product () is the ratio of the number of Al atoms in () to the number of Ti atoms in titanium tetrachloride (Al/Ti ) from 0.05 to 10, preferably from 0.06 to
It is 0.2. After the reaction is completed, the liquid part is separated and removed by decantation, and then washing is repeated with a solvent to obtain the solid product ().
may be used in the next step while suspended in a solvent, or may be further dried and taken out as a solid for use. The solid product () is then given an electron donor
(A) and electron acceptor (B) are reacted. Although this reaction can be carried out without using a solvent, preferable results are obtained when an aliphatic hydrocarbon is used. The amount used is (A)10 for 100g of solid product ().
g ~ 1000g, preferably 50g ~ 200g, (B) 10g ~
1000g, preferably 20g-500g, solvent 0-3000
ml, preferably 100-1000 ml. These three or four substances are mixed at -10°C to 40°C for 30 seconds to 60 minutes, and then mixed at 40°C to 200°C, preferably 50°C to 100°C for 30 minutes.
It is desirable to allow the reaction to occur for a period of seconds to 5 hours. There is no restriction on the order in which the solid products (), (A), (B), and the solvent are mixed. Before mixing (A) and (B) with the solid product (),
It is also possible to react with each other in advance; in this case,
After reacting (A) and (B) at 10 to 100°C for 30 minutes to 2 hours,
Use one that has been cooled to below 40℃. After the reaction of solid product () with (A) and (B) is completed, the reaction mixture is separated or removed by decantation to separate and remove the liquid portion, and washing with a solvent is repeated to remove unreacted liquid raw materials to produce a solid product. () is obtained.
The obtained solid product (2) can be dried and taken out as a solid product, or can be left suspended in a solvent for the next use. The solid product () thus obtained is
0.1 to 500 g of organoaluminum compound per g
The catalyst of the present invention is prepared by combining a predetermined amount of the aromatic ester and an aromatic ester described below, or, more preferably, by reacting and preactivating an α-olefin and then adding the ester. Organoaluminum compound used in the present invention ()
is expressed by the general formula AlRnR'n'X ₃ -(n+n'). In the formula, R and R' are an alkyl group, an aryl group,
It represents a hydrocarbon group or an alkoxy group such as an alkaryl group or a cycloalkyl group, and X is fluorine, chlorine,
It represents halogens such as bromine and iodine, and n and n' represent arbitrary numbers satisfying 0<n+n'3. Specific examples include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-butylaluminum, tri-n-hexylaluminum, tri-i-hexylaluminum, tri-2-methylpentylaluminum, tri-n- -Trialkyl aluminums such as octyl aluminum and tri-n-decyl aluminum, diethylaluminum monochloride, di-n-propyl aluminum monochloride, di-i-butyl aluminum monochloride, diethylaluminium monofluoride, diethylaluminium monobromide, diethylaluminium Examples include diethylaluminum monohalides such as monoiodide, alkylaluminum hydrides such as diethylaluminum hydride, alkylaluminum halides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum dichloride, i-butylaluminum dichloride, etc. In addition, alkoxyalkylaluminums such as monoethoxydiethylaluminum and diethoxymonoethylaluminum can also be used. These organoaluminum compounds can also be used in combination of two or more. The organoaluminum compound () to obtain the reaction product () and the organoaluminum compound () combined with the solid product () may be the same or different. As the electron donor (A) used in the present invention, various ones are shown below, but it is preferable to mainly use ethers and to use ethers in combination with other electron donors. Those used as electron donors include organic compounds having an atom of oxygen, nitrogen, sulfur, or phosphorus, such as ethers, alcohols, esters, aldehydes, fatty acids, ketones, nitriles, amines, These include amides, ureas or thioureas, isocyanates, azo compounds, phosphines, phosphites, phosphinites, thioethers, thioalcohols, and the like. Specific examples include diethyl ether, di-n-propyl ether, di-n-butyl ether, diisoamyl ether, di-n-pentyl ether, di-n-hexyl ether, di-hexyl ether, di-n-octyl ether, di-i- octyl ether, di-n
-Ethers such as dodecyl ether, diphenyl ether, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran; alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, phenol, cresol, xylenol, ethylphenol, and naphthol; methyl methacrylate, ethyl acetate, butyl formate, amyl acetate, vinyl butyrate,
Vinyl acetate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, 2-ethylhexyl toluate, methyl anisate, ethyl anisate, propyl anisate, Esters such as ethyl cinnamate, methyl naphthoate, ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, and ethyl phenylacetate, aldehydes such as acetaldehyde and benzaldehyde, formic acid, acetic acid, propionic acid, Fatty acids such as butyric acid, oxalic acid, succinic acid, acrylic acid, maleic acid, etc., aromatic acids such as benzoic acid, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone and benzophenone, nitriles such as acetonitrile, methylamine, diethylamine, tributylamine,
Amines such as triethanolamine, β(N,N-dimethylamino)ethanol, pyridine, quinoline, α-picoline, N,N,N',N'-tetramethylhexaethylenediamine, aniline, dimethylaniline, formamide, hexa Methyl phosphoric acid triamide, N, N, N', N', N''-pentamethyl-N'-β-dimethylaminomethyl phosphoric acid triamide, amides such as octamethylpyrophosphoramide, N, N, N', Ureas such as N'-tetramethylurea, isocyanates such as phenyl isocyanate and tolyl isocyanate, azo compounds such as azobenzene, ethylphosphine,
Phosphines such as triethylphosphine, tri-n-butylphosphine, tri-n-octylphosphine, triphenylphosphine, triphenylphosphine oxide, dimethylphosphine, di-n
- Phosphites such as octyl phosphite, triethyl phosphite, tri-n-butyl phosphite, triphenyl phosphite, ethyl diethyl phosphite, ethyl butyl phosphite,
Phosphites such as phenyl diphenyl phosphinite, thioethers such as diethyl thioether, diphenyl thioether, methyl phenyl thioether, ethylene sulfide, propylene sulfide, thioethers such as ethyl thio alcohol, n-propyl thio alcohol, thiophenol, etc. You can also give alcohol etc. These electron donors (A) can also be used in combination. The electron acceptor (B) used in the present invention is typified by a halide of an element in groups 1 to 10 of the periodic table. Specific examples include anhydrous aluminum chloride, silicon tetrachloride, stannous chloride, tin chloride, titanium tetrachloride, zirconium tetrachloride, phosphorus trichloride, phosphorus pentachloride, vanadium tetrachloride, antimony pentachloride, etc. These can also be used in combination. Most preferred is titanium tetrachloride. The following solvents are used. Examples of aliphatic hydrocarbons include n-heptane, n-octane,
i-octane etc. are indicated, and carbon tetrachloride, chloroform, dichloroethane, trichlorethylene,
Halogenated hydrocarbons such as tetrachlorethylene can also be used. As aromatic compounds, aromatic hydrocarbons such as naphthalene, and their derivatives mesitylene, duurene, ethylbenzene, isopropylbenzene, 2-ethylnaphthalene, 1-
Examples include alkyl group-substituted products such as phenylnaphthalene, halides such as monochlorobenzene and orthodichlorobenzene, and the like. The solid product thus obtained ( ) is then combined with an organoaluminum compound ( ) and the above-mentioned aromatic ester and used as a catalyst in the polymerization of propylene according to a conventional method, or more preferably, an α-olefin is polymerized. It is used as a preactivated catalyst by reaction. As the organoaluminum compound (), a dialkylaluminum monohalide represented by the formula (AlR ₁ R ₂ X) is preferable. During the ceremony
R ₁ and R ₂ represent a hydrocarbon group such as an alkyl group, an aryl group, an alkaryl group, a cycloalkyl group, or an alkoxy group, and X represents a halogen such as fluorine, chlorine, bromine, or iotho. [Specific examples include diethylaluminium monochloride, di-n-butyl monochloride, and diethylaluminium monoiodide. ] For slurry polymerization or bulk polymerization, a catalyst containing a combination of a solid product () and an organoaluminum compound is sufficiently effective, but when used for gas phase polymerization, α-
It is preferable to use a product with higher activity that is preactivated by reacting olefin. When gas phase polymerization is performed following slurry polymerization or bulk polymerization, even if the catalyst initially used is the former, it may not be the same catalyst as the latter because the propylene reaction has already taken place during gas phase polymerization. Excellent effects can be obtained over time. Preactivation is carried out for 1 g of solid product ().
Organic aluminum 0.1g to 500g, solvent 0 to 50,
Hydrogen 0-1000ml and α-olefin 0.05g-5000
g Preferably using 0.05g to 3000g, 0℃ to 100
React α-olefin for 1 minute to 20 hours at °C,
It is desirable to react 0.01 to 2000 g, preferably 0.05 to 200 g of α-olefin per 1 g of solid product (). The reaction of α-olefin for preactivation can be carried out in an aliphatic or aromatic hydrocarbon solvent, or without using a solvent in a liquefied α-olefin such as liquefied propylene, liquefied butene-1, ethylene, propylene, etc. It is also possible to react in the gas phase. or,
It can also be carried out in the presence of a pre-obtained α-olefin polymer or hydrogen. There are various aspects of the preactivation method, for example, (1) a method in which an α-olefin is brought into contact with a catalyst in which a solid product () and an organoaluminum are combined to perform a slurry reaction, a bulk reaction, or a gas phase reaction; (2) a method of combining a solid product ( ) with an organoaluminum in the presence of an α-olefin;
(3) Methods (1) and (2) in which an α-olefin polymer coexists; (4) Methods (1), (2), and (3) in which hydrogen coexists, etc. There is. In the preactivation, an aromatic ester () can also be added in advance. The α-olefin used for preactivation is
Ethylene, propylene, butene-1, hexene-
1. Heptene-1 and other straight chain monoolefins, branched chain monoolefins such as 4-methyl-pentene-1, 2-methyl-pentene-1, 3-methyl-butene-1, and styrene etc. can. These α-olefins etc. may be the same as or different from the α-olefins etc. to be polymerized, and α-olefins etc. may be used in combination. After the preactivation, the solvent, organoaluminum compound, unreacted α-olefin, etc. can be removed by distillation under reduced pressure, and the dried powder can be used for polymerization. It can be used in a suspended state in a solvent that does not exceed the above range, or the solvent, unreacted α-olefin, and organoaluminum compound can be removed by decantation, or it can be dried and used as a powder. .
It is also possible to add an organoaluminum compound before polymerization. The preactivated catalyst thus obtained can convert propylene into n-hexane, n-heptane,
It can be carried out by slurry polymerization carried out in a hydrocarbon solvent such as n-octane, benzene, toluene, etc., or by bulk polymerization or gas phase polymerization carried out in liquefied propylene, but in order to increase the isotacticity of the resulting propylene polymer. For this, aromatic carboxylic acid ester (hereinafter referred to as aromatic ester) () is added to the solid product () / = 0.1 to 10.0 (molar ratio)
need to be added. If the aromatic ester is added too little, the isotacticity is insufficiently improved, and if it is added too much, the catalytic activity decreases, making it impractical. Specific examples of aromatic esters include ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, and 2-toluate.
- Ethylhexyl, methyl anisate, ethyl anisate, propyl anisate, ethyl cinnamate, methyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, ethyl phenyl acetate, and the like. The usage ratio of organoaluminum compound () and solid product () is Al/
Ti=0.1-100 (molar ratio), preferably 1-20. In this case, the number of moles of the solid product () essentially refers to the number of Tig atoms in (). The polymer crystallinity capable of exhibiting the effects of the present invention is such that the isotactic pentad fraction is in the range of 1P0.015logMFR+0.955 in relation to NMR.
The higher the MFR, the higher the P tends to be.
MFR is usually 0.03-2.0/g10 minutes. The polymerization temperature is usually 20-100°C, preferably 40-85°C.
If the temperature is too low, the catalyst activity will be low and it is not practical, and if the temperature is too high, it will be difficult to increase the isotacticity. The polymerization pressure is normal pressure -50 kg/cm ² G, and the polymerization is usually carried out for about 30 minutes to 15 hours. During polymerization, steps such as adding an appropriate amount of hydrogen to adjust the molecular weight are the same as in conventional polymerization methods. The polypropylene of the present invention is produced as follows. That is, propylene is polymerized in at least two stages using the aforementioned catalyst system consisting of a solid product (2), an aromatic ester, an organoaluminium compound, and a molecular weight regulator. Hydrogen can be used as a molecular weight modifier. The polymerization conditions (temperature, pressure, time) can be carried out within known ranges, and the polymerization format can be any known method including bulk polymerization, suspension polymerization, and gas phase polymerization as long as the multistage polymerization of the present invention is possible. You can also do it. The simplest two-step polymerization will be explained below. In the present invention, the first stage polymer portion (A)
It is desirable that the amounts of the part (B) in the second stage are close to the same, and specifically, both are 35 to 65% by weight based on the total amount of (A) + (B), preferably 40%. ~60% by weight. If the quantitative ratio of (A) and (B) differs beyond the above range, sufficient melt flowability will not be obtained for the obtained polypropylene, and the kneading effect during granulation will be insufficient, resulting in a homogeneous final product. Not only is it difficult to obtain a molded product, but the degree of improvement in melt viscoelasticity is also small. Furthermore, the molecular weight difference between both polymer parts must also be within a certain range as shown in formula (1) below. Therefore, the polymerization conditions are controlled by adjusting the gas phase hydrogen concentration. now,
If the intrinsic viscosity of the high molecular weight part (135C, in tetralin solution) is [η] _H and the intrinsic viscosity of the low molecular weight part is [η] _L , then both are: 3.0 [η] _H − [η] _L 6.5 ...(1 ) must be satisfied. This relationship is expressed as
This substantially corresponds to (2). That is, [η] _H − [η] _L
At 3.0, logHMI < 0.922logMI + 1.44, meaning that the melt flow characteristics during melting for processing polypropylene are insufficient, and the degree of improvement in melt viscoelasticity is also insufficient, making it impossible to prevent sagging during secondary processing of the sheet. . On the contrary, [η] _H − [η] _L ＞6.5
In this case, the molecular weight difference between the above-mentioned parts (A) and (B) becomes excessive, and as a result, the non-uniformity of the molecular weight between the polypropylene particles increases, and as a result, the surface of a molded article made from such polypropylene becomes significantly rough. The above-mentioned polymer part (A) was produced with [η] _L = 0.7 to 2.5, and the above-mentioned polymer part (B) was produced with [η] _H = 5.0.
Preferably, a polymer of ~7.2 is prepared. The melt flow index (M ₁ ) of the polypropylene of the present invention obtained as described above is 0.03.
to 2.0 g/10 minutes is preferred. Below 0.03,
Since the fluidity of the melt during granulation or molding is poor, a large amount of power is required, which is not economical, and the surface of the resulting molded product becomes noticeably rough, resulting in a loss of commercial value.
Moreover, if it exceeds 2.0, the manufactured sheet will sag during secondary processing, making the processing difficult. Incidentally, the above equation (1) describes the polymer design method necessary to impart viscoelasticity to polypropylene that makes it possible to prevent the material to be molded from sagging during thermoforming of polypropylene sheets or blow molding of polypropylene. It shows. Similarly, the above-mentioned formula (2) indicates the flowability of polypropylene, and the polypropylene of the present invention having the polymer structure of formula (1) satisfies the condition of formula (2). The polypropylene for highly rigid molded products of the present invention can be widely applied to various molding fields and can exhibit its effects. For example, in the field of injection molding, the use of high-rigidity polymers such as polystyrene and ABS, which could not be used in the past, has been expanded, the quality has improved due to higher rigidity, and the higher rigidity has made molded products thinner than conventional products. It becomes possible to Therefore, effects such as cost reduction due to resource saving and improved molding speed can be expected. Furthermore, when a nucleating agent and inorganic filler are used together, high rigidity that could not be achieved with conventional products can be achieved, and if it is sufficient to maintain the same level of rigidity as conventional products, the amount of resin used can be reduced. . Similarly, in the film field, effects such as improved workability in automatic packaging etc. due to improved rigidity and reduced costs due to thinner walls can be obtained. The methods for measuring various physical properties in each of the Examples and Comparative Examples described below were as follows. Physical property method for Γ injection molded products Melt flow index (MI); ATM
D-1238, load 2.16 melt flow index (HMI);
ASTM D-1238, load 10.8 used Intrinsic viscosity [η]; 135℃ in tetralin However,
The limiting viscosity [η] ₂ of the first stage was determined by the following formula. That is, the intrinsic viscosity of the first stage [η] ₁ , the intrinsic viscosity of the entire polymer produced through the first and second stages [η] _T , the polymerization of the polymer portion produced in the first and second stages The ratios a and b were measured and determined from [η] _T =a[η] ₁ +b[η] ₂ =a[η] ₁ +(1-a)[η] ₂ . Isotactic pentad fraction (P);
Macromolecules 8 687 (1975). This is the isotactic fraction of pentad units in the polypropylene molecular chain using ¹³ C-NMR. Young's modulus Tensile yield strength ASTM D888 ASTM D882 (Kgf/mm ² ) Examples are shown as average values of TD and MD. EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. Example 1 (1) Preparation of catalyst 600 ml of n-hexane, 0.50 mol of diethylaluminium monochloride (DEAC), and 1.20 mol of diisoamyl ether were mixed at 25°C for 1 minute.
The mixture was allowed to react at the same temperature for minutes to obtain a reaction product solution (2.4 molar ratio of diisoamyl ether/DEAC). Titanium tetrachloride in a reactor purged with nitrogen.
4.0 mol was added, heated to 35°C, and the entire amount of the reaction product solution () was added dropwise over 180 minutes.
The temperature was kept at the same temperature for 30 minutes, the temperature was raised to 75℃, the reaction was continued for another hour, and the n-
The operation of adding 4000 ml of hexane and removing the supernatant liquid by decantation was repeated four times to obtain 190 g of a solid product (2). With the entire amount of this () suspended in 3000 ml of n-hexane, 160 g of diisoamyl ether and 350 g of titanium tetrachloride were heated at 20°C.
was added over about 1 minute at room temperature and reacted at 65°C for 1 hour. After the reaction was completed, it was cooled to room temperature (20°C) and the supernatant liquid was removed by decantation.
Add 4000 ml of n-hexane, stir for 10 minutes, leave to stand, and remove the supernatant liquid. After repeating the procedure 5 times,
Drying under reduced pressure gave a solid product (). (2) Adjustment of preactivated catalyst After purging a stainless steel reactor with internal volume 20 with inclined blades with nitrogen gas, 15
, 42g of diethylaluminum monochloride,
After adding 30 g of solid product () at room temperature, hydrogen
Add 15N, propylene partial pressure 5Kg/cm ² G to 5
React for minutes, unreacted propylene, hydrogen and n
- Hexane was removed under reduced pressure to obtain preactivated catalyst () in the form of powder (1 g of solid product ()).
82.g of propylene per reaction). (3) Polymerization of propylene In a polymerization vessel with an internal volume of 50 and replaced with _N2 , 20 g of dried n-hexane, 8 g of diethylaluminium monochloride, and the preactivated catalyst ()
2 g and 2.2 g of methyl P-toluate were charged, hydrogen was added, and the inside of the vessel was maintained at 70°C. Next, propylene was supplied into the vessel, and the pressure inside the vessel was increased to 10Kg/
cm ² , the hydrogen concentration in the gas phase was 11%, and the first stage polymerization was carried out at a temperature of 70°C. When the amount of polymerization reached 3 kg, the supply of propylene was stopped, the temperature inside the vessel was cooled to room temperature, and propylene that had not reacted with hydrogen was discharged. Then, a portion of the polymerization slurry was taken out and used for measuring [η] and analyzing the Ti content in the polymer by fluorescence X-ray method to determine the polymer yield per unit weight of catalyst. Then, the temperature inside the polymerization vessel was raised to 70℃ again and the polymerization pressure was increased.
The second stage polymerization was carried out at 10 Kg/cm ² G and while maintaining the gas phase hydrogen concentration at 0.4%. When the amount of polymerization in the second stage reached 3 kg, the supply of propylene was stopped, the temperature inside the vessel was cooled to room temperature, and hydrogen and unreacted propylene were discharged. Next, a part of the polymerization slurry was extracted, and [η] _T was measured and the Ti content in the polymer was analyzed by fluorescence X-ray method to determine the polymer yield per unit weight of catalyst.
Using the yield values of the stages, the ratio of the polymerization amounts of the first stage and the second stage was determined. To the polymerization slurry after the release, methanol from step 5 was added and stirred at 90°C for 30 minutes, then 40ml of 20% NaOH aqueous solution was added, and further 20%
Stir for 1 minute. Next, the mixture was cooled to room temperature, water 5 was added thereto, water washing and water separation were performed three times, and the obtained slurry was dried at high temperature to obtain a white polymer powder. The analysis results of the polymer are shown in Table 1. (4) Manufacture and evaluation of the sheet; Add BHT to 5 kg of the white polymer powder obtained in (3) above.
(2.6-di-t-butyl-P-cresol) 5g,
Irganox1010 (tetrakis [methylene (3,5-di
-t-butyl-4-hydrocinnamate]
methane) and 10 g of Calcium stearate were added and granulated. The granules were then processed at 225°C using a 50mmφ extrusion molding machine to form a product with a width of 60cm and a thickness of 0.4mm.
A sheet was prepared. In order to evaluate the heating vacuum formability of this sheet as a model, the sheet was
It was fixed in a 40cm x 40cm frame and placed in a thermostatic chamber at 200°C to measure the following physical properties. In other words, A. Sheet drooping amount (mm), B. Maximum return amount (Note {1/150×
(150 - amount of drooping at maximum repetitions) x 100}) and c) It is the holding time from the maximum number of repetitions until the drooping restarts. Table 1 also shows the Young's modulus and tensile yield strength of the sheet. A material with good vacuum formability according to the above evaluation method refers to a material with minimum droop, return amount, and long holding time. Furthermore, a high-rigidity material refers to a material with a high Young's modulus and a high tensile yield strength. Examples 2 to 4 In Example 1, the hydrogen concentrations in the first and second stages were changed to 5, 14, 25% and 25% in the order of example numbers.
The same procedure was carried out except that the concentrations were 0.07, 0.08, and 0.03%.
The results are shown in Table 1. Comparative Example 1 In Example 1, the hydrogen concentration in the first stage was set to 0.8%.
The same procedure was carried out except that the polymer yield was 6 kg and the second stage polymerization was omitted. The results are shown in Table 1. Comparative Examples 2 and 3 Same as Example 1 except that the hydrogen concentration in the first stage and the hydrogen concentration in the second stage were set to 3.2, 50% and 0.2, 0.015% in the order of example numbers, respectively. It was carried out in The results are shown in Table 1. As is clear from Comparative Examples 1 and 2 in the same table, when there is no or small difference in molecular weight between the first and second stage polymer parts, logHMI -
0.922logMI<1.44, and the vacuum formability of the polymer was poor. On the other hand, if the difference in [η] between the first and second stage polymer parts is too large as in Comparative Example 3, the surface of the sheet becomes rough, and although the vacuum formability is good, The commercial value of the molded product is lost. Ultimately, as mentioned above, in order to impart sufficient vacuum formability to the polymer of the present invention, [η] _H −
[η] _L is preferably 3.0, and [η] _H - [η] _L is required to be 6.5 in order to prevent roughening of the sheet surface.

[Table] Examples 5 and 6 In Example 1, the hydrogen concentrations in the first and second stages were 18, 5.0%, and 0.09 in the order of example numbers.
The same procedure was carried out except that the polymerization ratio was 0.03% and the polymerization ratios of the first stage and second stage were 4:6 and 6:2. The results are shown in Table 2. Comparative Examples 4 and 5 The same procedure as in Example 1 was carried out except that the hydrogen concentrations in the first and second stages were changed to 21 and 3% and 0.35 and 0.015%, respectively, in the order of the comparative example numbers.
The results are shown in Table 2. Comparative Examples 6 and 7 The same procedure as in Example 1 was carried out except that the hydrogen concentrations in the first stage and second stage were changed to 1.0 and 25% and 0.025 and 0.35%, respectively, according to the comparative example numbers.
The results are shown in Table 2. According to the same table, the MI of the polymer of Comparative Example 6 was too low and the flow of the melt was poor, making it impossible to form a good sheet. On the contrary, comparative example 7
The MI of this polymer was too high, so when the formed sheet was heated, it sank down and did not recover. Examples 8 and 7 The same procedure as in Example 1 was carried out except that the hydrogen concentrations in the first stage and second stage were changed to 0.10% and 13%, respectively. The results are shown in Table 2. As is clear from the table, the polymer portion with high molecular weight may be produced in the first stage as in this example, or it may be produced in the second stage as in Example 1. .

[Table] Note *1: Sheet production is not possible due to poor flow. *2: The sheet sags due to heating and does not return.
Example 8 The same procedure as in Example 1 was carried out except that the hydrogen concentrations in the first and second stages were changed to 18% and 0.06%, respectively. Using pellets obtained by granulating the obtained polymer, 10 bottles were manufactured by blow molding instead of sheet molding, and the bottles had a good appearance and a small thickness deviation. That is, the wall thickness ratio between the top and bottom portions of the bottle body was 0.92, which was a good value. Other polymerization results are shown in Table 3. Comparative Examples 8 and 9 The present invention was carried out in the same manner as in Example 8, except that the hydrogen concentrations in the first and second stages were respectively set to 1.2%, 45%, 0.70%, and 0.015% in the order of Comparative Example No. Polymerization and blow molding were carried out. Regarding uneven wall thickness of the obtained bottles, Comparative Example 8 had a poor wall thickness ratio of 0.63, and Comparative Example 9 had a good wall thickness ratio of 0.89, but the latter had a large surface roughness of the molded product and had a poor appearance. . Other polymerization results are shown in Table 3. Comparative Example 10 In Example 1, titanium tetrachloride was reduced with metal aluminum instead of the preactivated catalyst (),
The same procedure was carried out except that 8 g of a commercially available pulverized activated catalyst (AA type) and 8.8 g of methyl toluate were used, and the hydrogen concentrations in the first and second stages were set to 7.5% and 0.08%, respectively. . The results are shown in Table 3. Comparative Example 11 20 g of anhydrous magnesium chloride, 10 mm of ethyl benzoate and 6 ml of methylpolysiloxane were ground in a ball mill for 100 hours. 15 g of the solid product obtained were suspended in 200 ml of titanium tetrachloride,
After stirring at 80℃ for 2 hours, remove the liquid by filtration.
Further, the solution was washed with n-hexane until no titanium tetrachloride was detected in the solution, and then dried to obtain a solid catalyst. 2 g of this solid catalyst was used in place of the preactivated catalyst ( ) of Example 1, the addition of MPT was omitted and 2 g of TEA was used, and the hydrogen concentration in the first stage and second stage was 4.5, respectively. The same procedure was carried out except that the concentration was 0.05%. The results are shown in Table 3. Comparative Example 12 In Example 1, during the reaction to obtain the solid product (), 0.5 mol of DEAC was used instead of the reaction product (), and the temperature was 0°C instead of 35°C. After dropping the mixture, the temperature was raised to 75°C, and the reaction was stirred for another 1 hour.
Then, at the boiling temperature of titanium tetrachloride (approximately 136℃),
After being refluxed for a period of time to change the color to purple, after cooling, it was washed with n-hexane in the same manner as in Example 1.
The mixture was filtered and dried to obtain a solid catalyst. 8g of this solid catalyst
was used in place of the solid catalyst () in Example 1, and 8.8 g of methyl toluate was used in the first and second stages.
The same procedure was carried out except that the hydrogen concentration in each stage was 4.5% and 0.07%, respectively. The results are shown in Table 3.
As is clear from Comparative Examples 10, 11, and 12, when a catalyst other than the catalyst of the present invention is used, a highly rigid polypropylene such as that of the present invention cannot be obtained even if an aromatic ester is added.

[Table] Examples 9, 10, 11 Example 1 was carried out by changing the amount of MPT as shown in Table 4. In addition, the hydrogen concentrations in the first and second stages were set to 4.5, 6.5, and 9.0, respectively, in the order of the examples.
% and 0.07, 0.12, 0.14%. The results are shown in Table 4. Comparative Examples 13 and 14 Comparisons were carried out in Example 1 with the amount of MPT changed as shown in the table. In addition, the hydrogen concentrations in the first and second stages were 3.5%, 11.0% and 11.0%, respectively, in the order of the comparative example.
It was carried out at 0.06 and 0.15%. Furthermore, Comparative Example 14 is
The amount of polymerization in the first stage and second stage is 0.5 each.
Kg. If the amount of aromatic ester in Comparative Example 13 is less than the range of the present invention, the improvement in rigidity will be insufficient, and if it exceeds the range of the present invention, as in Comparative Example 14, the polymerization rate will be extremely slow, making it impractical. .

[Table] Note *3: The polymerized amount was less than 2 kg and sheet evaluation was not possible.
Examples 12, 13, 14, 15, 16, 17 In Example 1, the hydrogen concentrations in the first and second stages were respectively 13% and 0.06%, and instead of MPT,
Using the following aromatic esters Symbol Example 12: Ethyl P-toluate 2.4: a, 13: Butyl P-toluate 2.8 g: b, 14: Methyl benzoate 2.0 g: c, 15: Methyl benzoate 2.2 g: d, 16: methyl P-anisate 2.4 g: e, 17: ethyl P-anisate 2.6 g: f, carried out in the same manner. The results are shown in Table 5. Examples 18, 19, 20 In Example 1, the hydrogen concentrations in the first and second stages were set to 13% and 0.06%, respectively, and the organic Al compound
Use the following instead of DEAC Symbol Example 18 Di-n-propylaluminum; g, monochloride 19 Di-i-butylaluminum monoa; h, nochloride 20 Di-ethylaluminum monoa; carried out. The results are shown in Table 5.

【table】

【table】 [Brief explanation of drawings]

FIG. 1 is a flow sheet illustrating the method of the present invention.

Claims (1)

[Claims] 1. A solid product () obtained by reacting an organoaluminum compound () or a reaction product () of an organoaluminum compound () and an ether (A) with titanium tetrachloride (C), Furthermore, the solid product () obtained by reacting the ether with titanium tetrachloride (B) is combined with an organoaluminum compound () and an aromatic carboxylic acid ester () to produce the aromatic carboxylic ester and the solid product (). Propylene is polymerized in multiple stages in the presence of a catalyst with a molar ratio of / = 0.1 to 10.0, and in the first stage, 35 to 65% by weight of the total polymerization amount is converted to 65 to 35% by weight in the second and subsequent stages. % polymerized,
In the first stage, a polymer with [η] _L = 0.7 to 2.5 is produced, and in the second stage, a polymer with [η] _H = 5.0 to 7.2 is produced. The second part of the polymer part
The limiting viscosity of the step part [η] _H and the limiting viscosity of the first stage part [η] _L are 3.0 [η] _H − [η] _L 6.5 ...(1) As shown, the limiting viscosity of each polymer part is A method for producing high-rigidity and high-melt viscoelastic polypropylene, which is characterized by adjusting the value. 2. The method for producing polypropylene according to claim 1, wherein the melt flow index (MI) is 0.03 to 2.0 g/10 minutes. 3. The method for producing polypropylene according to claim 1, wherein the organoaluminum compound () is a dialkyl aluminum monohalide. 4. The method for producing polypropylene according to claim 1, wherein the combination of the solid product (2) and the organoaluminum compound is preactivated by reacting with α-olefin. 5 Isotactic pentad fraction (P)
The relationship with MFR is 1.00P0.015log MFR+
A method for producing polypropylene according to claim 1, wherein the polypropylene is within the range of 0.955. 6 Melt Flow Index (HMI) (10.80
Kg/10 minutes, 230℃) is the melt flow index (MI) (2.16Kg/10 minutes, 230℃) log HMI−0.922log MI1.44 ……(2) A method for producing polypropylene according to claim 1, in which the relationship is adjusted.